How LASIK Works
LASIK is a minor outpatient procedure that
corrects nearsightedness, farsightedness and astigmatism and
is intended to reduce or eliminate dependence on glasses and
contact lenses. During the procedure, Dr. Weinstock creates
a flap from the outermost layer of the cornea. The flap is
folded back revealing the middle section of the cornea. The
cool beam of the excimer laser removes tissue and gently
reshapes the cornea. The top layer of cornea is then
replaced to serve as a protective flap.
For nearsighted or myopic patients, the cornea is too steep. The LASIK procedure removes cells from the central part of the cornea flattening it for clearer vision.
For farsighted or hyperopic patients, the cornea is too flat. The LASIK procedure removes cells in a spiral pattern around the outside of the cornea. This steepens the cornea and creates clearer vision.
The flap is then replaced and for most patients has already healed significantly within twenty-four hours. The natural suction of the eye holds the flap in place. These permanent adjustments allow the cornea to reflect light onto the retina of the eye, resulting in normal focus.
The Evolution of LASIK
There were several laser vision correction procedures being performed before LASIK, short for Laser in Situ Keratomileusis. Through the developmental stages of laser vision correction surgeons noticed certain side effects and limitations with the original procedures. As time went on, each procedure developed a more predictable result and faster recovery. LASIK embodies the positives of ALK, RK and PRK without the pain and long recovery periods. The following will briefly highlight pros and cons of these procedures.
RK, or Radial Keratotomy, was
popular in the 1970's. The surgeon would make radial
incisions on the surface of the cornea, subsequently causing
it to sink down in the center creating a flatter cornea. The
procedure resulted in a painful recovery, largely due to the
scar tissue created by the incisions.
PRK, or Photorefractive
Keratectomy was the next improvement to vision correction.
Rather than making radial incisions on the cornea, an
excimer laser was used to sculpt and reshape the surface of
the cornea. With PRK, patients experienced gradual visual
improvement over a few days or even months and may have had
extended discomfort.
LASIK as with PRK, LASIK uses
an excimer laser. In this procedure, a corneal flap is
created with an instrument called a microkeratome. The flap
is folded back allowing the laser to gently reshape the
cornea and then is carefully replaced into its original position. The natural suction of the eye holds the flap in place much like the eye would do with a contact lens. With LASIK, patients experience virtually no pain, have no scar tissue and have highly predictable results.
The Procedure
